Hair curler heating device with electric resistance cable

ABSTRACT

A hair curler heater device having a base plate and a plurality of hollow cylindrical fingers mounted on and projecting from the base plate for receiving a hair curler to be heated. An electric resistance heating cable having high and low temperature sectors is arranged for heating the fingers. The high temperature sectors are accommodated within the fingers and the low temperature sectors are provided in the base plate. The heating cable has a core of flexible non-conducting material and a heating wire helically wound about the core so as to form the high and low temperature sectors. The low temperature sectors are formed by an odd number of layers of heating wire wound around the core in electrical contact with each other to form a plurality of partial resistors electrically connected in parallel. Alternate layers of the cold sectors are wound about the core in the same direction as the heating wire is wound about the core in the high temperature sectors and the number of layers in each of the low temperature sectors exceeds the number of layers in each high temperature sector by at least two.

United States Patent 191 Geominy et al.

[ Jan. 8, 1974 [22] Filed:

[ 4] HAIR CURLER HEATING DEVICE WITH ELECTRIC RESISTANCE CABLE {75] Inventors: Louis Joseph Henri Geominy;

Hubertus Johannes Josephus Gommans; Leonardus Frans Helene Mans; Silvester Marie Ruytenbeek, all of Venlo, Netherlands [73] Assignee: U. S. Philips Corporation, New

York, NY.

Nov. 8, 1971 211 Appl. No.: 196,275

Related U.S. Application Data [62] Division of Ser. No. 52,801, July 7, 19 0, Pat. No.

" iss/210414. 218; 132/33 R [56] References Cited UNITED STATES PATENTS 1,983,862 12/1934 Maness et al. 338/214 Primary Examiner-A. Bartis Attorney-Frank R. Trifari [5 7] ABSTRACT A hair curler heater device having a base plate and a plurality of hollow cylindrical fingers mounted on and projecting from the base plate for receiving a hair curler to be heated. An electric resistance heating cable having high and low temperature sectors is arranged for heating the fingers. The high temperature sectors are accommodated within the fingers and the low temperature sectors are provided in the base plate. The heating cable has a core of flexible nonconducting material and a heating wire helically wound about the core so as to form the high and low temperature sectors. The low temperature sectors are formed by an odd number of layers of heating wire wound around the core in electrical contact with each other to form a plurality of partial resistors electrically connected in parallel. Alternate layers of the cold sectors are wound about the core in the same direction as the heating wire is wound about the core in the high temperature sectors and the number of layers in each of the low temperature sectors exceeds the number of layers in each high temperature sector by at least two.

2 Claims, 3 Drawing Figures PMENTEDJ 3.784.784

' SHEET 1 (If 3 I INK 'EXTORS. LOUIS J. H. GEOMINY HUBERTUS J.J. GOMMANS LEONARDUS FRANS H. MANS BY SILVESTER M. RUYTENBEEK AGENT PATENTED JAN 74 SHEET 2 OF 3 INVEXTORS.

LOUIS J. H. GEOMINY HUBERTUS J.J. GOMMANS LEONARDUS FRANS.H. MANS B SILVESTER M. RUYTENBEEK V AGENT PATENTED JAN 8 I974 suwaur Fig.

HAIR CURLER HEATING DEVICE WITH ELECTRIC RESISTANCE CABLE This is a division of application Ser. No. 52,801, filed July 7, 1970, now U.S. Pat. No. 3,621,203, issued Nov. 16, 1971.

The invention relates to an electric resistance heating cable comprising a flexible core of electrically insulating material, a heating wire wound helically around this core and extending throughout the length of the cable and a covering of electrically insulating material. The cable is divided into at least two groups of alternating sectors extending along the cable. The different sectors produce different temperatures during use of the cable.

A cable of this kind is known from German Pat. No. 820,943. In this cable the heating wire in the sectors which have the low temperature during use is wound at a greater pitch than in the sectors which have a higher temperature during'use.

It has been found in practice that such a construction is not conducive to the manufacture of a cable having sectors of very great temperature differences (several hundred degrees of Celsius). The temperature of the heating wire itself exhibits little differences in the different sectors.

A further construction of such a cable is described in U.S. Pat. No. Re 26,522. i

1n the electric resistance heating cable disclosed in this patent sectors whose temperature does not increase or only increase to a relatiely low value during use are obtained by short-circuiting a number of windings of the heating wire at different distances along the cable by means of a conducting strip. The strip is provided between the core and the windings of the heating wire. 1

when such a cable is kinked or is repeatedly bent there is the risk that the ends of the strips will slide out from the windings of the resistance .wire and be bent, thereby damaging the insulating outer covering and causing a short circuit between the cable and other metal parts which are in the vicinity of the cable during use. In addition, local variations of the resistance of the cable occur.

In the proposed construction it is not quite clear how sectors having a relatively low temperature and small dimensions are to be obtained. 1

An object of the present invention is to provide a construction for an electric resistance heating cable which avoids the drawbacks of the known constructions.

According to the invention, an electric resistance heating cable which satisfies the above is characterized in that an odd number of helically wound layers of heating wire are provided in the sectors of the cable which produce a relatively low temperature during use. These are in electrical contact with one another and these alternate layers are wound in the same direction as that in whichthe heating wire is wound in the sectors having a higher temperature during use. The number of layers provided one across the other exceed the number of layers in the high temperature sectors by at least tWO.

In this connection a heating wire is understood to mean a wire of arbitrary shape and optionally a composite structure.

By using the construction according to the invention, sectors which extend in the longituninal direction of the cable may be obtained in a simple manner without using other materials than that for the heating wire itself, which sectors have mutually different resistances per unit length and consequently a mutually different heat development during use.

The occurrence of a temperature difference results exclusively from the special construction of the cable according to the invention.

In one suitable embodiment three layers of heating wires are arranged one across the other in the low temperature sectors of the cable, while the heating wire is wound in a single layer in the higher temperature sec tors.

Electrically, such a cable comprises a plurality of sectors having a comparatively high resistance and a plurality of sectors having a comparatively low resistance. The latter sectors are produced by winding the heating wire in such a manner that a plurality of partial resistors is produced each of which convey only a part of the current which is passed through the heating wire in the other sectors. The plurality of partial resistors present in a given sector determines the temperature which is reached during use in said sector, as a function of the load.

the heating wire may be wound at the same or a different pitch in the different sectors and in the layers located one on top of the other.

It is also possible to vary the pitch within a sector during winding so that a certain temperature profile is obtained within a sector.

In a suitable embodiment in which three layers of heating wire are located one on top of the other in the low temperature sectors, the first two layers located on the core are wound at a greater pitch than is the third layer. When using this construction a greater tempera ture difference is produced between the different sectors than in a construction in which the first two layers located on the core are wound at a pitch which is equal to that of the third layer. Winding of the third layer at a small pitch produces a satisfactorily electrical contact between the different layers and facilitates the application of contacts which are reliable in operation. The desired temperature difference may of course alternatively be obtained by winding a number of layers, greater than three one across the other at the same small pitch. However, the preferred embodiment provides a considerable economy in material as compared with such a constructionf The core of the cable may consist of any electrically insulating organic or inorganic material which is resistant to the temperatures prevailing during use of the cable. The core may have a single or composite structure and may comprise, for example, polyvinylchloride, silicon rubber, nylon, glass fibre, asbestos fibre, polytetrafluoroethylene and polyfluoroethylene propylene.

A central conductor may be provided within the core. This conductor extends throughout the length of the core and may be used for connector purposes when it is difficult to loop the cable or to establish contact in a different manner.

The heating wire may in principle comprise any electrically conducting material. However, a material having a high positive temperature coefficient of the specific resistance is preferably used (0.002 or more per C) for example, nickel, copper. In fact, as a result thereof the temperature difference in a given construction is increased and in case of a prescribed temperature difference less material may suffice' than when using materials having a low temperature coefficient.

Depending on the temperatures occurring during use the outer covering may consist of organic or inorganic materials, which are known for this purpose. In principle the same materials may be used as those which are suitable for the core.

The cable may be produced by' passing the core, which will generally have a circular cross-section, continuously in one direction through a winding device and to cause this device to perform a forward and backward movement along the core when single layers are to be wound one on top of the other. According to a further method a fixed winding point is used and the core is moved forward and backward when single layers are to be wound one on top of the other. The core wound with the resistance wire is subsequently provided with an outer covering, for example, by winding and/or pleat ing it with glass or asbestos fibres or rayon or cotton, or by passing it through an extrusion device by which the cable is provided with a synthetic resin covering.

The outer covering may optionally consist ofa plurality of apertures bodies of ceramic material.

Since it is desirable to be able to recognize the different heating sectors when the cable is not in use, for example, when mounting it in apparatus or when providing connecting pieces, it is recommended that the outer covering be appropriately marked or labelled. In the covered cable the relative low temperature sectors can be found back by magnetic or electric means because of the presence of a greater quantity of metallic mate rial. A marking device may be coupled to a device suit able for this purpose.

Cables according to the invention may be used in apparatus in which heat must be generated locally while the intermediate parts of the apparatus and the connecting points must not increase or increase only to a slight extent in temperature.

Cables according to the invention may be used, for example, in heaters for hair curlers in principle consisting of a plurality of hollow cylinders or fingers to be heated which project from a bottom plate onto which the hair curlers can be slid. The sectors of the cable which reach a high temperature during use are accommodated in the fingers while the parts which remain comparatively cold are provided in the bottom plate.

Cables according to the invention may also be used in defrosters for refrigerators.

In order that the invention may be readily carried into effect, embodiments thereof will now be described in detail by way of example.

In this respect reference is made to the accompanying drawing in which FIGS. l and 2 show on an enlarged scale cable sections according to the invention, and FIG. 3 shows a heater for a hair curler using the cable of the invention.

The cable has a glass fibre core 1. A heating wire 2 is wound on the core. In the sectors A, which are partially visible, the heating wire 2 is wound in a single layer, the resistance being 30 ohms per metre. The sectors A reach a temperature of approximately 400C during use at a load of 90 Watts per metre. In the sectors B one of which is visible in the Figure, the heating wire 2 is wound in three layers. In the first layer, which is directly located on the core l, the heating wire 2 is wound at a pitch which is approximately 20 times greater than the pitch in the sectors A (wire parts denoted by the reference numerals 3 and 4 in the Figure) in the same direction (in the Figure to the right-hand side) as in the previous sector A. In the layer provided thereupon (wire parts denoted by the reference numerals 5 and 6) the heating wire is likewise wound at this greater pitch, but now in the opposite direction. In the third layer (starting from the wire part denoted by the reference numeral 7) theheating wire is again wound at the same pitch and in the same direction'as in the previous sector A(in the Figure to the right-hand side). The temperature insector B is approximately 509C dur ing use. The length of the sectors B is equal to that of the sectors A. The electrically insulating covering 8 of the cable may be a glass-fibre pleat having an overall thickness of 0.5 mm;

The cable of FIG. 2 has a central conductor 10 provided with a glass-fibre envelope 111 as a core. A heating wire 12 is wound on this core. The heating wire is wound in a single layer 12 in the visible sector A of the cable. In the sector B the heating wire is wound in three layers as described with reference to FIG. 1. Furthermore, the cable has an outer covering 13 and two end pieces 14 and 15. The end piece 14 serves to connect the heating wire T2 to the central conductor 10, being for example, a copper wire of low resistance. To this end the end piece l4 comprises an outer envelope 16 of electrically insulating material and a metal bush 17 which fits around the core including heating wire 12, which metal bush includes a metal cylinder 18 fitting around the central conductor. The end piece 15 acts as an electrical contact. It consists of a bush of electrically insulating material which is provided with a metal inner bush 20 supporting a contact pin 21. The end piece also supports a metal hollow pin 22 accommodating the part of the central conductor 10 protruding from the envelope.

Since the heating wire 12 is wound in different layers in the sector, B, the temperature in this sector does not become very high. The covering 19 of the end piece may therefore consist of synthetic resin.

The advantage of this embodiment of the heating cable is that the electrical contact of the cable may be established on one side thereof.

FIG. 3 shows the cable as used in a heater 25 for hair curlers. The heater has a base plate 26 and hollow cylindsical fingers 27 projecting from the plate for receiving thereon hair curlers to be heated. The cable extends through the base plate 26 and fingers 27 with the high temperature sectors A being accommodated within the cylindrical fingers 27 so as to provide heat for the curlers and the low temperature sectors B being accommodated in the base plate.

What is claimed is:

l. A hair curler heater device comprising a base plate, at least one hollow cylinder mounted on and projecting from said base plate for receiving thereon a hair curler to be heated, an electric resistance heating cable having high and low temperature sectors arranged for heating said hollow cylinder, said high temperature sector being accommodated within said cylinders and said low temperature sectors being provided in said base plate, said heavint cable comprising a core of flexible non-conducting material, a heating wire helically wound about said core so as to form said high and low temperature sectors, said low temperature sectors being formed by an odd number of layers of heating wire in electrical contact with each other, alternate layers being wound about said core in the same direction as the heating wire wound about the core through the high temperature sector, said number of layers in the low temperature sector exceeding the number of layers in the high temperature sector by at least two, and an electrically insulating covering about said cable.

2. A hair curler heater device comprising a base plate, at least one hollow cylinder mounted on and projecting from said base plate for receiving thereon a hair curler to be heated, an electric resistance heating cable having high and low temperature sectors arranged for heating said hollow cylinder, said high temperature sector being accommodated within said cylinders and said low temperature sectors being provided in said base plate, said heating cable comprising a core of flexible ering about said cable. 

1. A hair curler heater device comprising a base plate, at least one hollow cylinder mounted on and projecting from said base plate for receiving thereon a hair curler to be heated, an electric resistance heating cable having high and low temperature sectors arranged for heating said hollow cylinder, said high temperature sector being accommodated within said cylinders and said low temperature sectors being provided in said base plate, said heavint cable comprising a core of flexible non-conducting material, a heating wire helically wound about said core so as to form said high and low temperature sectors, said low temperature sectors being formed by an odd number of layers of heating wire in electrical contact with each other, alternate layers being wound about said core in the same direction as the heating wire wound about the core through the high temperature sector, said number of layers in the low temperature sector exceeding the number of layers in the high temperature sector by at least two, and an electrically insulating coveRing about said cable.
 2. A hair curler heater device comprising a base plate, at least one hollow cylinder mounted on and projecting from said base plate for receiving thereon a hair curler to be heated, an electric resistance heating cable having high and low temperature sectors arranged for heating said hollow cylinder, said high temperature sector being accommodated within said cylinders and said low temperature sectors being provided in said base plate, said heating cable comprising a core of flexible non-conducting material, a heating wire helically wound about said core so as to form said high and low temperature sectors, said low temperature sectors comprising means cooperating with said heating cable to define a plurality of partial resistors electrically connected in parallel, each resistor conveying only part of the current conveyed by the heating wire in the high temperature sector, and an electrically insulating covering about said cable. 